igmp-snooping router-learning (VLAN view)

Function

The igmp-snooping router-learning command enables router port learning in a VLAN.

The undo igmp-snooping router-learning command disables router port learning in a VLAN.

By default, router port learning is enabled in a VLAN.

Format

igmp-snooping router-learning

undo igmp-snooping router-learning

Parameters

None

Views

VLAN view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

A router port is located on a Layer 2 device and connects to an upstream Layer 3 device (a multicast router or Layer 3 switch). A switch running IGMP snooping considers an interface as a dynamic router port when the interface receives an IGMP General Query message with any source IP address except 0.0.0.0 or a PIM Hello message. If the switch does not need to receive Query messages or PIM Hello messages from a VLAN, disable router port learning in the VLAN. A router port provides the following functions:

Receives multicast data from the upstream device.
Forwards IGMP Report/Leave messages. IGMP Report/Leave messages received in a VLAN are forwarded only to router ports in the VLAN.

By default, router port learning is enabled on an interface. To prevent interfaces in a VLAN from becoming a router port, disable router port learning in the VLAN.

Prerequisites

IGMP snooping has been enabled globally using the igmp-snooping enable (system view) command.

Follow-up Procedure

The switch does not listen on IGMP Query messages in a VLAN after router port learning is disabled in the VLAN. To ensure normal multicast forwarding in the VLAN, run the igmp-snooping static-router-port command to configure a static router port.

Precautions

If IGMP snooping is disabled in the specified VLAN, the configuration succeeds but does not take effect until IGMP snooping is enabled in the VLAN. To enable IGMP snooping in a VLAN, run the igmp-snooping enable (VLAN view) command.

You can also disable router port learning by running the undo igmp-snooping router-learning (interface view) command. The undo igmp-snooping router-learning (interface view) command is the same as the undo igmp-snooping router-learning (VLAN view) command only except for the scope they take effect. The command used in the VLAN view disables router port learning on all interfaces in a VLAN, whereas the command used in the interface view disables router port learning on a specific interface in a VLAN.

When inter-VLAN multicast replication is enabled on the switch, enable router port learning in user VLANs.

Example

# Disable router port learning in VLAN 3.

<HUAWEI> system-view
[HUAWEI] igmp-snooping enable
[HUAWEI] vlan 3
[HUAWEI-vlan3] igmp-snooping enable
[HUAWEI-vlan3] undo igmp-snooping router-learning